fold(1)fold(1)NAMEfold - fold long lines for finite width output device
width] [file ...]
width] [file ...]
The command is a filter that folds the contents of the specified files,
breaking the lines to have a maximum of width column positions (or
bytes, if the option is specified). The command breaks lines by
inserting a newline character so that each output line is the maximum
width possible that does not exceed the specified number of column
positions (or bytes). A line cannot be broken in the middle of a char‐
acter. If no files are specified or if a file name of is specified,
the standard input is used.
The command is often used to send text files to line printers that
truncate, rather than fold, lines wider than the printer is able to
If the backspace, tab, or carriage-return characters are encountered in
the input, and the option is not specified, they are treated specially
Backspace The current count of line width is decremented
by one, although the count never becomes nega‐
tive. Thus, the character sequence character-
backspace-character counts as using one column
position, assuming both characters each occupy
a single column position. does not insert a
newline character immediately before or after
any backspace character.
Tab Each tab character encountered advances the
column position pointer to the next tab stop.
Tab stops are set 8 columns apart at column
positions 1, 9, 17, 25, 33, etc.
Carriage-return The current count of line width is set to zero.
does not insert a newline character immediately
before or after any carriage-return character.
Note that may affect any underlining that is present.
The command recognizes the following options and command-line argu‐
Count width in bytes rather than in column positions.
Break the line on the last blank character found
before the specified number of column positions
(or bytes). If none are found, break the line
at the specified line length.
Specify the maximum line length, in column posi‐
tions (or bytes if
is specified). The default value
is 80. width should be a multi‐
ple of 8 if tabs are present, or
the tabs should be expanded using
before processing by (see
expand(1)). The option is obso‐
lescent and may be removed in a
determines the interpretation of text as single- and/or
determines the language in which messages are displayed.
If or is not specified in the environment or is set to
the empty string, the value of is used as a default for
each unspecified or empty variable. If is not specified
or is set to the empty string, a default of "C" (see
lang(5)) is used instead of
If any internationalization variable contains an invalid
setting, behaves as if all internationalization variables
are set to "C". See environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.